Outer Limits 4x4 Board

ok well there is always alot of talk on here about what turbo people should fit to there 4wd. I had this problem when i was looking at what turbo i should fit. trying to get info out of a shop is hard. a few people i have talked to have said you need to see what rpm it makes a certain boost. anyway i was thinking of a little table that people could come and fill out for others to see how there turbos compare. i was thinking of there being a template people could copy and paste.

TEST TO BE CARRIED OUT IN 4TH GEAR ON A FLAT ROAD

VECHILE-
ENGINE-
GEARBOX-
TURBO-
FUEL ADJUSTED-
INTERCOOLER-
DIFF RATIOS-
TYRE SIZE-
EXHAUST SIZE-
MAX BOOST-
RPM AND KM/HR AT 5 PSI-
RPM AND KM/HR AT 10 PSI-
RPM AND KM/HR AT MAX BOOST-
MAX EGT-



so for example you would copy the template and then fill it out like so

TEST TO BE CARRIED OUT IN 4TH GEAR ON A FLAT ROAD

VECHILE- landcruiser 80 series
ENGINE- 1hdt
TURBO- gt2871r 56 trim .64turbine
FUEL ADJUSTED- no
INTERCOOLER- no
DIFF RATIOS-4.11
TYRE SIZE- 285/75x16
EXHAUST SIZE- 3inch
MAX BOOST- 12 psi
RPM AND KM/HR AT 5 PSI- 1700rpm/50km/hr
RPM AND KM/HR AT 10 PSI- 2300rpm/65km/hr

please comment and post any suggestion and maybe the mods may make it a sticky. anything else that should be in the list. remember if it does go to a sticky i think it should be just result and no chit chat.

What about speed at said rpm ? I know that 4th gear 70klm/hr with my set up is about 3-5 lbs of boost.
Thats with 4.3's and 33's.

The big variable and the dealbreaker would be exhaust setup.

No two modified vehicles will have the same exhaust clearance ability (manifold volume and diameter pre-turbo, exhaust length/diameter, muffler/resonator placement along exhaust length, etc) and therefore the turbo parameters will be so different as to be meaningless as a comparison tool.

Even similar sized turbos can have different internals (A/R ratio, turbine masses, bearing types, etc) effecting the overall outcome.

added a couple of changes so far. i understand that no 2 vechiles will be the same but i thought that this could be a good base for people that have fitted a turbo can compare to others or those looking to fit a turbo can see what others have achieved and if they wanted more info they could pm the individually for more info.

keep it coming guys.

VECHILE- Rangerover Classic
ENGINE- Isuzu 4BD1T
GEARBOX- Isuzu truck 5 speed.
TURBO- T25, 0.49 A/R exhaust.
FUEL ADJUSTED- Yes. Factory adjustment unknown.
INTERCOOLER- No.
DIFF RATIOS- 3.54
TYRE SIZE- 29" roughly.
EXHAUST SIZE- 2.25 (too small)
MAX BOOST- 20psi from about 1600rpm.
RPM AND KM/HR AT 5 PSI- not much above idle.
RPM AND KM/HR AT 10 PSI- 1300rpm, 50km/h.
Max EGT- Try to keep it under 750, has seen 900 accidentally a few times.

This turbo could produce more boost than backpressure below 2000rpm if EGT's were above 650C.

I have since replaced this turbo with a home built T2560 for better topend, but it hasn't been fully tested.

KiwiBacon,
why no intercooler?

Serg

ledgend80 wrote:ok well there is always alot of talk on here about what turbo people should fit to there 4wd. I had this problem when i was looking at what turbo i should fit. trying to get info out of a shop is hard. a few people i have talked to have said you need to see what rpm it makes a certain boost.

yes because you select a turbo on what horse power you want, so if you have 300 hp now but want 500hp then you work out what rpm you want the 500hp at and you also want to work it out because you probably don't really want to blow up your motor either, and by the same token don't want to shell out $1500 on a lump of metal that does nothing to improve performance.

the freebie way of getting the maths you require is to get the triple K, H or IHI PDF from a euro company and it will have a list of all the their turbo and the compression charts, but the main thing is it has the simple maths of working out the RPM of your motor and what the RPM's you want for the amount of HP your actually after.

That applies to ALL motors and ALL turbos.

hope that helps you.

zagan wrote:

ledgend80 wrote:ok well there is always alot of talk on here about what turbo people should fit to there 4wd. I had this problem when i was looking at what turbo i should fit. trying to get info out of a shop is hard. a few people i have talked to have said you need to see what rpm it makes a certain boost.

yes because you select a turbo on what horse power you want, so if you have 300 hp now but want 500hp then you work out what rpm you want the 500hp at and you also want to work it out because you probably don't really want to blow up your motor either, and by the same token don't want to shell out $1500 on a lump of metal that does nothing to improve performance.

the freebie way of getting the maths you require is to get the triple K, H or IHI PDF from a euro company and it will have a list of all the their turbo and the compression charts, but the main thing is it has the simple maths of working out the RPM of your motor and what the RPM's you want for the amount of HP your actually after.

That applies to ALL motors and ALL turbos.

hope that helps you.

cheers for that i understand that. i guess what i am really trying to achieve from this is that people can come and see what others have achieved with the turbo they have fitted. so if someone is wanting to fit one they can see what others have achieved.

i also added a couple more to the original template

uninformed wrote:KiwiBacon,
why no intercooler?

Serg

I simply haven't got around to it. I've owned suitable intercoolers for at least 4 years and still have one in a box.
One day. Too many projects, not enough time or money to deal with them all.

I think max EGTs after a WOT run from say 2000rpm to redline would be a useful benchmark too

80's_delirious wrote:I think max EGTs after a WOT run from say 2000rpm to redline would be a useful benchmark too

All that measures is the lag you have in your EGT probe.

KiwiBacon wrote:

uninformed wrote:KiwiBacon,
why no intercooler?

Serg

I simply haven't got around to it. I've owned suitable intercoolers for at least 4 years and still have one in a box.
One day. Too many projects, not enough time or money to deal with them all.

it will flow better if you take it out of the box

a non intercooled isuzu is still better than a dead 300tdi

VECHILE- landcruiser 75 series
ENGINE- 1hz-t
TURBO- gt2876r 70 trim .64turbine
FUEL ADJUSTED- yes
INTERCOOLER- yes
DIFF RATIOS- 4.88
TYRE SIZE- 40x13.5r17
EXHAUST SIZE- 3inch
MAX BOOST- 25 psi
RPM AND KM/HR AT 5 PSI- appx1000rpm/55km/hr
RPM AND KM/HR AT 10 PSI- appx1800rpm/70km/hr
Max EGT 450